000 AXPZ20 KNHC 140357 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Mar 14 2018 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0330 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: 1022 mb high pressure centered near Tampico Mexico continues to support gale force winds across the Gulf of Tehuantepec. Reinforcing high pressure will build from the southern plains into the lower Mississippi Valley early today, perpetuating the gale force winds and associated seas to 13 ft. The plume of strong winds and high seas will reach 300 nm downstream of the Gulf of Tehuantepec by late today. The gradient will start to weaken tonight as the supporting high pressure shifts eastward, although local drainage effects will continue to support minimal gales into early Thu morning. Winds and seas diminish substantially thereafter through Thu as the gradient weakens. Please see the latest Pacific Ocean High Seas Forecast product under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough axis extends from 09N84W to 05N95W. The intertropical convergence zone continues to 05N95W to 04N140W. Scattered moderate convection is noted from 04N to 06N between 80W and 85W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for details on an ongoing Gulf of Tehuantepec gale event. High pressure of 1019 mb centered near 25N123W is maintaining generally moderate northwesterly winds across the region with 5 to 7 ft seas off the coast of Baja California and 3 to 5 ft in the Gulf of California. Winds and seas will diminish into early Wed as the high pressure shifts eastward and weakens ahead of a cold front approaching from the west. The front will move across Baja California Norte and the northern Gulf of California this morning before dissipating late today over the Sonoran Desert. Strong westerly gap winds are possible over northern Baja California into the Gulf of California Wed night, then diminish as the front moves farther southward and weakens. Long period NW swell in excess of 8 ft will move into the waters off Baja California beginning Wed following the front. The swell will propagate to the waters of Baja California Sur by late Thu before decaying below 8 ft. Winds and seas will continue to diminish into Fri as high pressure builds over the region. Beyond 48 hours, southwest winds will increase and another round of NW swell ahead of another cold front moving west across the region. Strong westerly gap winds are again possible into the northern Gulf of California Fri night into Sat as the front moves through the region. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Over Gulf of Papagayo, high pressure ridging over the Caribbean will bring fresh to strong NE to E winds through Fri night as the pressure gradient re-strengthens in response to high pressure building southeastward over the Caribbean from the Gulf of Mexico. Over the Gulf of Panama, gentle to moderate winds will prevail through mid week, increasing to moderate to fresh thereafter. Winds may briefly be strong off the Azuero peninsula late Thu. Seas are expected to be in the range of 4 to 6 ft as moderate cross- equatorial SW swell propagates through these waters, building the seas 5 to 7 ft Thu and Fri as the winds also increase. Elsewhere, expect gentle to moderate winds and 4 to 6 ft seas to prevail, except seas of 8 to 11 ft in northerly swells generated from a gale force gap wind event in the Gulf of Tehuantepec, which will propagate into the Guatemala offshore waters tonight through Tue night. REMAINDER OF THE AREA... A cold front extends from near 32N122W to 23N128W and is dissipating to 23N132W. The front will shift eastward across the waters north of 20N into early Wed. Areas of rain with embedded scattered showers are noted within 120 nm to the east of the front from 25W to 28N. NW swell is propagating into the region behind the front, with seas in excess of 8 ft and reaching 10-15 ft N of 28N and W of 130W. These seas will subside through Wed. NW to N swell producing seas in the range of 8-10 ft will slowly subside to the west of about 118W through Thu. $$ Christensen